A switch for sensing displacement

ABSTRACT

A switch for closing an electric circuit upon movement of either or both of two members in either direction which includes a double contact and a contact disposed between the elements of the double contact which are movable to bring the contact and one of the elements of the double contact together upon movement of either or both of the two members in either direction. The switch also includes means for varying the clearance between the contact and the elements of the double contact when the former is centered with respect to the latter in order to vary the sensitivity of the switch.

[451 Oct. 24, 1972 United States Patent Wernig mu h HAmm ll/ mmmw "W2 c mmm ee LNHS d r m a HGSH 00600 3247 9999 mmwm mm ,93 59 729 2 23 m 5 6 m mm K m W n s e N w m m T U RN a 0 E n M m H E J K CC TA r WP n SE w AD .m m m Primary Examiner-Robert K. Schaefer Assistant Examiner-M. Ginsburg Attorney-A. F. Baillio April 19, 1971 [22] v Filed:

R lated .S. A ta e U ABSTRACT [62] Division of Ser. No. 869,697, Oct. 27, i969.

A switch for closing an electric circuit upon movement of either or both of two members in either direction which includes a double contact and a contact disposed between the elements of the double con- Mm N wh Wm 2 6" W n St Um 211 55 [l [58] FieldofSearch.........200/6l.44, 11 K, 31, 19 A, tact which are movable to brin g the contact and one 200/22 155 155 6145 of the elements of the double contact together upon 166 M movement of either or both of the two members in either direction. v

[56] References Cited UNITED STATES PATENTS The switch also includes means for varying the clearance between the contact and the elements of the double contact when the former is centered with muau ne 6" menm mmmn c a mfikh h en S G 3038 3736 9999 1111 ll// 6976 6 083 6 6 4 2 3179 1318 9 ,9 I 13 PATENTEDnm 24 m2 SHEET 1 OF 2 INVENTOR. James H. Wernig PA'TENTEDucI-u I972 3.700.841

sum 2 0F 2 INVENTdR. James H. Wernig 1 A SWITCH FOR SENSING DISPLACEMENT SUMMARY OF INVENTION This application is a division of my prior application, Ser. No. 869,697, filed Oct. 27, 1969.

This invention relates to switches for closing electrical circuits.

The principal object of the invention is to provide an electric switch which is responsive to movement of either or both of two members in any direction to close a circuit.

Another object is to provide means for varying the open circuit clearance between the contacts of the switch to vary the sensitivity of the switch.

For a better understanding of the nature and objects of this invention, reference is made to the following specification and accompanying drawing wherein the preferred embodiment of the invention is described and shown.

BRIEF DESCRIPTION OF DRAWING FIG. 1 is a perspective view of the front end of an automotive vehicle equipped with protective shields for the front seat occupants and a part of the rear end of a preceding vehicle.

FIG. 2 is a side elevation of the shields and the actuator therefor in the vehicle.

FIG. 3 is a perspective exploded view of the switch for activating the actuator and its mounting bracket with parts of the switch in section.

FIG. 4 is a sectional view of the switch at an angle to FIG. 3.

FIG. 5 an exploded perspective view of the conductive rings and the interposed insulating disc of the switch.

DESCRIPTION OF PREFERRED EMBODIMENT The automotive vehicle shown in the drawing includes a frame (not visible), and a body 10, front fenders 11 and a front bumper 12 mounted on the frame. The body defines the compartment for the driver and passengers and has a windshield 13 at its front end. Forward of the body is an engine compartment which is defined by the front fenders l1 and a hood 14. The front fenders are tied together near their forward ends by a cross member 15.

Above the windshield 13 are mounted to swing from the stored position in which they are shown in solid lines to the operational position in which they are shown in dash lines in FIG. 2 two-part protective shields 30 and 82 for the front seat occupants of the vehicle. To swing the shields from their stored to their operational positions, there is provided a spring actuator 18 normally retained in cocked position by a solenoid-released detent (not visible).

To activate the solenoid 55, there is provided a normally open switch '58 mounted on a bracket 59which is secured to the cross member which extends between the front fenders of the vehicle. One terminal of the switch is connected by a wire 60 to one terminal of a power source, such as the storage battery of the car, and the other terminal of the switch is connected by a wire 61 to one terminal of the coil of the solenoid. The other terminals of the battery and coil are grounded so that current is supplied to the coil when the switch is closed.

The switch 58 includes two body members 63 and 64 of insulating material mounted to rotate with respect to each other on a shouldered screw 65 which also with a nut 94 secures the switch to the bracket 59. On the inner faces of the body members are mounted conductive'rings 66 and 67 which carry interfitting contacts 68 and 69. The rings are separated and held against axial displacement with respect to the body members by an insulating disc 70 which clamps the semi-circumferences of the rings opposite those which carry the contacts against the body members. However, the opening 71 through the disc 70 is enlarged opposite the semi-circumferences of the rings which carry the contacts so that these portions of the rings and the contacts they carry may be moved toward and away from each other. The contacts are held against circumferential displacement with respect to the body members on which they are mounted by the wires 60 and 61 which are soldered to them and seated in grooves 74 and 75 in the faces of the body members.

The contacts are normally centered with respect to each other with their side faces separated and may be held in this position during installation of the switch by a pin 76 which extends into holes in the body members which register when the contacts are centered. The side faces of the contacts are inclined and the ring 67 is made of flexible spring material with its outer face opposite the contact 69 in line with a screw 77 which is threaded into the body member 64. The screw 77 can be turned to move the contact 69 toward and to allow it to move away from the ring 66 and thus move the side faces of the contacts toward or away from each other to vary the circumferential movement required to bring side faces into contact.

To operate the switch, there is provided on each of the body members an arm 78. One of the arms is connected to one of the fenders 11 by a rod 79 and the other to the bumper 12 by a rod 80. In each of the rods, there is installed a turnbuckle 81 to adjust its length.

The rods 79 and 80 are installed with the switch contacts held in centered (open) position by inserting the pin 76 in the openings in the body members which register when the contacts are centered and are adjusted in length by use of the turnbuckles 81 so that the contacts remain centered when the pin is removed. The screw 77 is adjusted to position the contacts so that any displacement of the fenders, bumper or cross member 'beyond that incident to normal vibration of the car will result in bringing one set of contacts together and activating the solenoid.

Because the fenders, bumper and cross member are relatively easily crushed or displaced, such a front end collision will displace one or more of them sufficiently to close the contacts 68 and 69 a fraction of a second before anything sufficiently solid, such as the engine or the frame, is encountered to significantly decelerate the vehicle and throw the front seat occupants toward the windshield with injurious force. The switch thus activates the actuator in advance of significant deceleration of the vehicle or movement of the occupants toward the windshield by inertia instead of simultaneously as inertia actuators do and thus affords this margin of time to get the shields 30 and 82 between the front seat occupants and the windshield and rear view mirror before their heads strike the windshield.

Iclaim:

1. An electric switch which includes a dielectric body a contact which includes a spaced pair of elements, another contact which includes a third element between the pair of elements, the contacts being mounted on the body so that one of them can move back and forth relatively to the other and the elements limit movement of the contacts relatively to each other, and means mounted on the body by which one of the contacts can be moved back and forth between a position in which the third element is in contact with one of the pair of elements and a position in which it is in contact with the other.

2. An electric switch which includes a dielectric body, a contact which includes a spaced pair of elements, another contact which includes a third element between the pair of elements, the contacts being mounted on the body so that each of them can move back and forth relatively to the other and the elements limit movement of the contacts relatively to each other, and means mounted on the body by which each of the contacts can be moved back and forth between a position in which the third element is in contact with one of the pair of elements and a position in which it is in contact with the other.

3. An electric switch which includes a dielectric body, a pair of contacts which include rings mounted on the body to rotate opposite each other and insulated from each other by the body, interfitting projections on the rings spaced from each other circumferentially of the rings, and means for rotating each of the rings back and forth between a position in which the intermediate projection is in contact with one of the projections and a position in which it is in contact with another projection on the other ring.

4. An electric switch which includes two contacts with parallel inclined surfaces which face each other, means for moving one of the contacts toward the other in one direction to bring the inclined surfaces together and close the switch, and means for moving one of the contacts toward the other in another direction crosswise of the first direction and holding it in different positions with respect to the other contact in such direction to vary the spacing of the inclined surfaces and the distance it has to be moved in the first direction to close the switch.

5. The switch claimed in claim 3 in which the interfitting projections have parallel inclined faces, plus means to move a projection carrying portion of one ring toward the other ring and hold it in different positions with respect to the other ring in such direction to vary the distance between the inclined surfaces circumferentially of the rings. 

1. An electric switch which includes a dielectric body a contact which includes a spaced pair of elements, another contact which includes a third element between the pair of elements, the contacts being mounted on the body so that one of them can move back and forth relatively to the other and the elements limit movement of the contacts relatively to each othEr, and means mounted on the body by which one of the contacts can be moved back and forth between a position in which the third element is in contact with one of the pair of elements and a position in which it is in contact with the other.
 2. An electric switch which includes a dielectric body, a contact which includes a spaced pair of elements, another contact which includes a third element between the pair of elements, the contacts being mounted on the body so that each of them can move back and forth relatively to the other and the elements limit movement of the contacts relatively to each other, and means mounted on the body by which each of the contacts can be moved back and forth between a position in which the third element is in contact with one of the pair of elements and a position in which it is in contact with the other.
 3. An electric switch which includes a dielectric body, a pair of contacts which include rings mounted on the body to rotate opposite each other and insulated from each other by the body, interfitting projections on the rings spaced from each other circumferentially of the rings, and means for rotating each of the rings back and forth between a position in which the intermediate projection is in contact with one of the projections and a position in which it is in contact with another projection on the other ring.
 4. An electric switch which includes two contacts with parallel inclined surfaces which face each other, means for moving one of the contacts toward the other in one direction to bring the inclined surfaces together and close the switch, and means for moving one of the contacts toward the other in another direction crosswise of the first direction and holding it in different positions with respect to the other contact in such direction to vary the spacing of the inclined surfaces and the distance it has to be moved in the first direction to close the switch.
 5. The switch claimed in claim 3 in which the interfitting projections have parallel inclined faces, plus means to move a projection carrying portion of one ring toward the other ring and hold it in different positions with respect to the other ring in such direction to vary the distance between the inclined surfaces circumferentially of the rings. 